Multi-contact medical electrode devices are placed in the human body for various purposes, such as brain-mapping in epilepsy treatment. In such treatments wires generally extend from the multi-contact medical electrode to a plural-contact tail. The plural-contact tail is linear in shape and contains an array of sleeve-like contacts spaced therealong. The plural contacts of the plural-contact tail are to facilitate quick electrical connection of the contacts of the multi-contact medical electrode device such as for monitoring, recording and analysis purposes. Connectors have been configured to simultaneously engage the contacts of the plural-contact tail for their individual electrical connection to separate wire strands which emerge from the connector.
Various connectors have been developed to facilitate plural-contact connection. Examples of such prior art plural-contact medical connectors are those disclosed in the following United States patents: U.S. Pat. No. 4,850,359 (Putz). U.S. Pat. No. 4,869,255 (Putz), U.S. Pat. No. 6,415,168 (Putz), U.S. Pat. No. 4,744,371 (Harris), U.S. Pat. No. 5,560,358 (Arnold et al.). U.S. Pat. No. 5,902,236 (Iversen), U.S. Pat. No. 4,516,820 (Kuzma). U.S. Pat. No. 4,712,557 (Harris), U.S. Pat. No. 4,461,304 (Kuperstein), U.S. Pat. No. 4,379,462 (Borkan et al.), U.S. Pat. No. 4,633,889 (Talalla et al.) and U.S. Pat. No. 4,676,258 (Inokuchi et al.).
Some medical connectors of the prior art have a number of shortcomings. One concern in a surgical setting that involves much equipment, many wires and hoses and the like, is that the connector be small in size to facilitate easy operation by medical personnel. It would be advantageous to have a connector which is small and slim so that it can be easily maneuvered by medical personnel during surgery. A slim design is particularly advantageous with respect to connectors that have a great number of contacts. Some connectors in the prior art are large in size and clumsy making them difficult to organize and manage. Certain prior art connectors utilized a flat ribbon-type cable that emerged laterally off the top of the connector giving the connector a bulky appearance. Other prior art connectors had a build-up of epoxy along the top of the connector that also added bulk.
When using a medical connector it is important that a constant and reliable electrical connection be present so that accurate information can be obtained. Some connectors in the prior art may create concerns with reliability of the connection. A reliable electrical connection is also of paramount importance since often the connectors are in use for lengthy periods of time. If a connector fails during use all of the information obtained may be lost or rendered inaccurate.
Medical connectors for use in patients who have a seizure tendency must also be secure. If a patient has a seizure there is the chance that the electrical connections could be destroyed or disrupted. Specifically, the plural-contact tails of multi-contact electrodes can become dislodged or broken by the involuntary movements that occur during a seizure. Therefore, it is important that the connector be secure so that it can withstand the jerking motions that are characteristic of seizures.
It would be also highly desirable to have a connector with an improved reliable contact between contacts of the plural-contact tail and the conductors of the connector device. This would ensure good electrical connections despite dimensional variations on the contacts of the tail.
In certain prior art devices the electrical connector is a connector of the type that includes a tail-receiving first elongate member having proximal and distal ends and a second elongate member with corresponding proximal and distal ends. The first elongate member has a presentation face which extends along the second elongate member and the first elongate member also includes a tail-receiving void. The second elongate member has a nesting surface and an array of electrical conductors. The nesting surface includes two faces set at right angles to one another; a pivot-axis-adjacent face and a pivot-axis-opposite face. The first elongate member has a lead edge. When the device is fully closed the lead edge is at the intersection of the pivot-axis-opposite face and the pivot-axis-adjacent face.
In certain prior art devices the electrical conductors along the second elongate member are spring-loaded ball plunger devices which are used to facilitate electrical contact with the plural contacts of the plural-contact tail. The spring-loaded ball plunger device has a plunger axis along which the ball has slight movement. In these devices electrical connection for each contact occurs by the ball riding across the contact of the plural-contact tail until it reaches its final position. In such prior art devices the plungers are positioned along the pivot-axis-opposite face so that engagement occurs when the tail-receiving void is moving in a direction approaching perpendicular to the axis of the spring-loaded ball plunger devices.
The spring-loaded ball plunger devices of the prior art have disadvantages. Most notably the ball on the plunger device does not have the ability to travel as far into the tail-receiving void. This directly effects the ability of the ball to contact the tail receiving void possibly leading to an inaccurate contact. The very nature of the movement of the ball across the contact of the plural-contact tail means there is potential for an inaccurate and unreliable contact.
In summary, there are a number of problems and shortcomings in prior connectors for use with multi-contact medical electrode devices.